Updates, refactoring, version() call

[sashee]

This PR does multiple things:

• update dependencies and add the package-lock.json (it should be committed to the repository)
• add the missing tslib dependency
• refactor tmpdir handling to be more cross-platform (uses the platform's tempdir) and safer (removed the tmps variable and the sync delete call)
• add a version() call that runs pdftocairo -v and prints the results

According to the tests and my experience these changes don't break existing functionality

[codecov]

Codecov Report

Merging #87 (27b128e) into master (9e35c6d) will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##            master       #87   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files            1         1           
  Lines          103       104    +1     
  Branches        48        49    +1     
=========================================
+ Hits           103       104    +1     

Impacted Files	Coverage Δ
src/index.ts	100.00% <100.00%> (ø)

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